#define _CRT_SECURE_NO_WARNINGS
//1.C version
#if 1
#include<stdio.h>
int main()
{
	int a, b, c,count=0;
	while (scanf("%d%d%d", &a, &b, &c) == 3)
	{
		if (a == 0 && b == 0 && c == 0)
			break;
		count++;
		printf("Case %d:%.*lf\n",count,c, (double)a / b);
	}
	return 0;
}
#endif
//2.C++ verison
#if 0
# include <iostream>
using namespace std;
int main() 
{
	int a, b, c, count = 0;
	while (cin >> a >> b >> c) 
	{
		if (a == 0 && b == 0 && c == 0)
			return 0;
		else
			printf("Case: %d: %.*lf\n", ++count, c, (double)a / b);
	}
	return 0;
}
#endif